Monodispersed Silica@Nickel Silicate Hydroxide Core-Shell Spheres for Supercapacitor Electrodes

摘要

Monodispersed silica@nickel silicate hydroxide core-shell microspheres are prepared using a hydrothermal method. The core-shell microsphere with an average diameter of 525 nm displays a hierarchical structure. The shell with an average thickness of about 40 nm consists of Ni3Si2O5(OH)(4) nanosheets yielding porous surface. Surface-dependent electrochemical property exhibits a specific capacitance of 356.7 F g(-1) at 0.5 A g(-1) and a good rate performance, which is attributed to the special core-shell hierarchical structures not only providing abundant electroactive sites for redox reaction but also shortening ion/electron transportation path. The current study provides a simple and efficient way to design low-cost electrodes for supercapacitors.